In a study conducted in a Chicago public housing development, women who lived in apartment buildings with trees and greenery immediately outside reported committing fewer aggressive and violent acts against their partners in the preceding year than those living in barren but otherwise identical buildings. In addition, the women in greener surroundings reported using a smaller range of aggressive tactics during their lifetime against their partner.

How can we explain this link between vegetation and less aggression? The women who reported a larger range of aggressive behaviors over their lifetime also had worse scores on a test of concentration, and living in an apartment with barren surroundings was linked to having worse scores on that same test. Low scores on tests of concentration can be caused by high levels of mental fatigue and this study demonstrated that those living in barren housing were both more fatigued and more aggressive. But exposure to green surroundings reduces mental fatigue and the feelings of irritability that come with it. The ability to concentrate is refreshed by green views, along with the ability and willingness to deal with problems thoughtfully and less aggressively. And, in this study, even small amounts of greenery—a few trees and a patch of grass—helped inner city residents have safer, less violent domestic environments.

This research was supported by the University of Illinois and by the USDA Forest Service Urban and Community Forestry Program on the recommendation of the National Urban and Community Forestry Advisory Council.